1. Field of the Invention
This invention relates to an improved glass or similar hard surface cleaning composition. More particularly, this invention relates to an aqueous hard surface cleaning composition, especially glass surfaces, of the general type disclosed in the Stonebraker, et al U.S. Pat. No. 3,463,735 in which a low molecular weight polyacrylic acid composition replaces the alkali metal polyphosphate builder component to provide improved cleaning capacity.
2. Discussion of the Prior Art
U.S. Pat. No. 3,464,735 to Stonebraker, et al discloses a glass cleaning composition of the type containing a solvent system consisting of a mixture of low boiling solvent and moderately higher boiling solvent and a surfactant, and preferably ammonia, in which the effectiveness of the glass cleaning composition is improved by incorporating therein an alkali metal polyphosphate, especially tetrasodium pyrophosphate. In fact, since the Stonebraker patent issued in 1969, the polyphosphate built compositions have consistently provided the most superior performance of all commercially available hard surface aqueous cleaning compositions with regard to such properties as fat and grease removal, wipe-off characteristics, and the like. Attempts to replace the alkali metal polyphosphate builders with alternative builders have met with only marginal success in view of the superior overall performance of the polyphosphate built compositions, as well as the cost benefits of the polyphosphates as compared to alternative builders.
In general, the practitioner in this field does not expect to find alternative builders for the alkali metal polyphosphates which can give equivalent enhancement of the cleaning capabilities of detergent compositions when used at the same weights, much less at lower weights, of the alternative builder.
For instance, in U.S. Pat. No. 3,706,672--Martin, et al an essentially phosphate-free detergent washing composition in which an organic alkaline builder-sequestrant selected from relatively high molecular weight alkali metal, ammonium or substituted ammonium polyacrylates having an inherent viscosity, in 2 normal sodium hydroxide in the range of about 0.05 to about 1.25, is provided. The reader is also referred to the prior art patents and literature referred to in columns 1 and 2 of the patent for other disclosures relating to acrylic acid polymers, copolymers and salts thereof as detergent builders.
U.S. Pat. No. 3,922,230--Lamberti et al discloses oligomeric polyacrylate biodegradable detergent builders useful in detergent compositions comprising said polyacrylate, which has a molecular weight between about 500 and 10,000, and a surfactant, the polyacrylate having biodegradable terminal groups selected from the group consisting of sulfur and hydroxy containing moieties. The ratio of builder to surfactant is in the weight ratio of 1:20 to 20:1.
Other U.S. patents broadly relating to acrylic acid polymers and copolymers or derivatives thereof for use in detergent compositions include the following: U.S. Pat. Nos. 3,719,647--Hardy, et al; 3,825,498--Altenschopfer, et al; 3,950,260--Eldib; 3,969,500--Kennerley; and 4,021,376--Lamberti, et al. U.S. Pat. No. 3,965,024 to Schmadel, et al discloses washing agent compositions and washing assistant compositions which contain from 0.5% to 70% by weight of a phosphonopolycarboxylate monomer.
However, none of these prior art compositions suggest the use of a low molecular weight polyacrylic acid, a salt thereof, and/or an acrylic acid polymeric resin complex containing inorganic phosphate or sulfur moieties for incorporation in glass cleaning compositions or similar hard surface cleaning compositions of the type disclosed by Stonebraker in the aforementioned U.S. Pat. No. 3,463,735.
A cleaning composition for glass and similar hard surfces similar to that of Stonebraker is disclosed by Labarge, et al in U.S. Pat. No. 3,696,043. This patent is based upon the incorporation of a water soluble polymeric salt which is a copolymer of one to two moles of a monovinyl aromatic monomer per mole of an unsaturated dicarboxylic acid or an anhydride thereof wherein the acid is neutralized with a sufficient amount of an amine, ammonia or an alkali metal base to form a solubilizing salt group or wherein the anhydride is neutralized by a sufficient amount of ammonia or a monoamine having no other groups reactive with the anhydride group to form a solubilizing salt group. The glass cleaning compositions of Stonebraker, et al and Labarge, et al are characterized by, and can be distinguished from, the light duty and heavy duty detergent compositions of the aforementioned patents such as the Hardy, et al patent, by the presence of an organic solvent system, especially an alcohol-glycol solvent system, among others. Moreover, the glass cleaning compositions to which the present invention is primarily concerned, can be functionally distinguished from the light duty dishwashing compositions and heavy duty laundry compositions as having a much lower level of active constituents and by the higher operating temperatures and foaming characteristics of the latter. In particular, the glass cleaning compositions and similar hard surface cleaning compositions to which the present invention is concerned, are applied directly to the surface to be cleaned at ambient room temperature, usually by pump or aerosol type spray applicators.